Oh

I play undertale on my nintendo switch so I can’t do that

Have you tried any of the undertale mods where you go into the different alternate universes where there's just a bunch of different versions of sans and his brother (Papyrus) and basically every monster in the game

no and if I did have to battle sans I would quit the game

If you find asgore so hard to beat did you even go on genocide the route? you know where you kill all the monsters? And then you have to challenge sans